A conventional process of manufacturing a semiconductor substrate (hereinafter, simply referred to as a “substrate”) involves various types of processing performed on the substrate by a substrate processing apparatus. For example, processing such as supplying a chemical solution to a substrate having a resist pattern on its surface and thereby etching the surface of the substrate is performed. After completion of the etching process, processing for removing the resist on the substrate and cleaning the substrate is also performed.
In a single-wafer substrate processing apparatus for processing substrates one at a time, a substrate is held by a substrate holding part, and a processing liquid is supplied to the substrate while rotating the substrate holding part. Various techniques are used for holding a substrate in the substrate holding part, such as vacuum chucking, mechanical chucking, or magnetic chucking. For example, U.S. Pat. No. 6,446,643 (Document 1) discloses a mechanism for clamping a substrate from above and below between upper and lower chamber members when these chamber members are arranged at positions close to each other, and releasing the clamp on the substrate when the chamber members are moved away from each other.
Japanese Patent Application Laid-Open No. 2005-19456 (Document 2) discloses a mechanism for holding and releasing the hold on a substrate by mechanically turning each of a plurality of holding members disposed around the substrate, using a motor as the power source. U.S. Pat. No. 6,485,531 (Document 3) discloses a technique for holding a wafer on a rotary head with a holding part having a spring, in an apparatus in which the rotary head rotates contactlessly relative to a stator by the magnetic force.
In the case where the substrate holding part is rotated in a floating state as with the apparatus of Document 3, it is difficult to transmit the driving force of a power source such as electricity or compressed air to the substrate holding part in order to hold the substrate. The apparatus of Document 3, in which a wafer is held by the holding part having a spring, requires complicated operations such as fixing the wafer to the rotary head outside a processing chamber and then introducing the rotary head with the wafer mounted thereon into the processing chamber.
In addition, the substrate holding part and the substrate tilt if it is attempted to release the hold on the substrate with an external force while the substrate holding part is still in the floating state. This compromises the reliability of substrate delivery.